The EPA wants to test a randomly selected sample of water specimens and estimate the mean daily rate of pollution produced by a mining operation. If the EPA wants a 98% confidence interval with a bound of error of 1 milligram per liter (mg / L) , how many water specimens are required in the sample ? Assume prior knowledge indicates that pollution readings in water samples taken during a day have been approximately normally distributed with a standard deviation of 5.8 mg/L)